Negative gauge pressure dynamic convection system having inner and outer airflow regulated environments for artificial limb and associated methods

ABSTRACT

The forced convection system includes a limb socket configured to define an outer regulated airflow environment between the socket and the liner, and an airflow generation device coupled to an inner airflow regulated environment and the outer regulated airflow environment and configured to generate airflow therein. A convection control system including convection control circuitry is configured to adjust the airflow generation device and configured to dynamically control airflow to maintain negative gauge pressure therein and transfer thermal energy therein to an external atmosphere. The convection control system further includes a rising edge triggered negative gauge pressure regulation device including pressure control circuitry and an associated valve configured to control airflow proportioning devices to open respective airflow paths to the regulated airflow environments. The convection control system is configured to provide regulated differential pressure forced airflow convection to the regulated airflow environments.

RELATED APPLICATIONS

This application is a Continuation Application of U.S. application Ser.No. 14/222,867 filed Mar. 24, 2014 which claims the benefit of U.S.Provisional Application Nos. 61/840,404 filed Jun. 27, 2013, 61/911486filed Dec. 4, 2013, all of which are hereby incorporated herein in theirentireties by reference.

FIELD OF THE INVENTION

The present invention relates to the field of artificial limbs, and,more particularly, liners employed in artificial limbs, related systemsand related methods.

BACKGROUND OF THE INVENTION

Tests measuring the thermal conductivity of 23 different commerciallyavailable prosthetic liners and common socket materials by Klute, G. K.,et al. (2007), in a paper titled “The thermal conductivity of prostheticsockets and liners” Prosthet Orthot Int., 31(3): p. 292-9 found that allsamples tested effectively trapped thermal energy. Hachisuka et al.(2001) in an article titled “Moisture permeability of the total surfacebearing prosthetic socket with a silicone liner: is it superior to thepatella-tendon bearing prosthetic socket?” J. Uoeh, 23, 225-32 foundthat an artificial limb liner seals off airflow to both the residuallimb and to the prosthetic socket, which results in an accumulation ofperspiration between the liner and limb.

Even relatively light activities like walking can cause substantialincreases in skin temperatures inside the prosthesis as reported byPeery, J. T., et al. (2005) in the paper titled “Residual-limb skintemperature in transtibial sockets. J Rehabil Res Dev. 42(2): p. 147-54.Shibasaki, M., et al. (2006), in a paper titled “Neural control andmechanisms of eccrine sweating during heat stress and exercise” J ApplPhysiol, 100(5): p. 1692-701; teaches as skin temperatures increase, thephysiological response can include both vasodilation and sympatheticstimulation of the limb's sweat glands. It is of interest to note thatvasodilation and sweat production continues to increase linearly withtemperature as taught by Parsons, K. C., (2003) in a paper titled “Humanthermal environments: the effects of hot, moderate, and coldenvironments on human health, comfort, and performance.” 2nd ed. 2003,London; New York: Taylor & Francis. xxiv, p. 527.

It can be extrapolated from the citations above that a wearing aprosthetic limb will result in an increasing rise in skin temperatureand increasing moisture accumulation. It's the insulative materials ofmodern prosthetic socket construction and suspension that trap heat anddeprive the skin of cooling through evaporation of perspiration. Thereis a need for an approach to reduce thermal energy buildup in anartificial limb dynamically throughout its duration of use.

SUMMARY OF THE INVENTION

In view of the foregoing background, it is therefore an object of thepresent invention to provide a forced convection system and a method tomanage excessive thermal buildup and consequently reduce the amount ofperspiration generated.

This and other objects, features, and advantages in accordance with thepresent embodiments may be provided by a forced convection systemconfigured to be attached to a residual limb of an amputee. The systemincludes a conformable convection liner configured to be donned over theresidual limb and define an inner regulated airflow environment betweenthe liner and the residual limb, a limb socket configured to receive theresidual limb and donned liner, and define an outer regulated airflowenvironment between the socket and the liner, and an airflow generationdevice coupled to the inner airflow regulated environment and the outerregulated airflow environment and configured to generate airflow withinthe inner regulated airflow environment and the outer regulated airflowenvironment. A convection control system including convection controlcircuitry is configured to adjust the airflow generation device andconfigured to dynamically control airflow within the inner regulatedairflow environment and the outer regulated airflow environment tomaintain negative gauge pressure therein and transfer thermal energytherein to an external atmosphere. A first airflow proportioning deviceis coupled to the inner regulated airflow environment, and a secondairflow proportioning device coupled to the outer regulated airflowenvironment. The convection control system further includes a risingedge triggered negative gauge pressure regulation device comprisingpressure control circuitry and an associated valve configured to controlthe first and second airflow proportioning devices to open respectiveairflow paths to the inner and outer regulated airflow environments. Theconvection control system is configured to provide regulateddifferential pressure forced airflow convection to the inner and outerregulated airflow environments with the rising edge triggered negativegauge pressure regulation device, the first and second airflowproportioning devices, and the airflow generation device.

In certain embodiments, the liner may include inflow air channels and atleast one outflow air channel in fluid communication with the innerregulated airflow environment, and the airflow generation device may becoupled to the inner airflow regulated environment via the inflow airchannels and/or the outflow air channel.

In certain embodiments, the airflow generation device comprises abattery operated airflow generation device or a body powered airflowgeneration device.

In certain embodiments, a textile layer, including a proximal seal, isconfigured to surround at least a portion of the residual limb and, withthe liner, define the inner regulated airflow environment between theliner and the residual limb. The textile layer may have a thickness thattapers from a distal end to a proximal end thereof.

In certain embodiments, a plurality of airflow convection guides are onthe exterior surface of the liner and comprise longitudinal scallopedchannels in fluid communication with respective distal airflow channels.The longitudinal scalloped channels may be configured to providepositive volumetric distortion within the socket during a stance phaseof the amputee.

In certain embodiments, the liner further includes a convection pinadapter at a distal end thereof and including a central convectionchannel configured to provide fluid communication between the innerregulated airflow environment and the airflow generation device, and aplurality of adapter convection holes configured to provide fluidcommunication between the outer airflow regulated environment and thecentral convection channel. The liner may further include internalairflow convection guides on an interior surface thereof and in fluidcommunication with the central convection channel of the convection pinadapter at the distal end of the liner. A hollow convection pin may beinterfaced with the convection pin adapter and include a distal outletport in fluid communication with the central convection channel of theadapter. A convection manifold may be configured to interface with thehollow convection pin and include a removable absorber configured toextract moisture from airflow in an airflow path to the airflowgeneration device. The convection manifold may include a mufflerconfigured to reduce noise in the airflow path.

In certain embodiments, each of the first and second airflowproportioning devices may be an electromechanical binary airflowproportioning device.

In certain embodiments, each of the first and second airflowproportioning devices may be a mechanical binary airflow proportioningdevice.

Objects, features, and advantages in accordance with the presentinvention may also be provided by a method of forced convection to aresidual limb of an amputee with an attached artificial limb. The methodmay include: providing a conformable convection liner to be donned overthe residual limb and defining an inner regulated airflow environmentbetween the liner and the residual limb; receiving the residual limb anddonned liner in a limb socket, and defining an outer regulated airflowenvironment between the socket and the liner; coupling airflowgeneration device to the inner regulated airflow environment and theouter regulated airflow environment and configured to generate airflowwithin the inner regulated airflow environment and the outer regulatedairflow environment; providing a convection control system includingconvection control circuitry configured to adjust the airflow generationdevice to dynamically control airflow within the inner regulated airflowenvironment and the outer regulated airflow environment to maintainnegative gauge pressure therein and transfer thermal energy therein toan external atmosphere; and coupling a first airflow proportioningdevice to the inner regulated airflow environment, and a second airflowproportioning device to the outer regulated airflow environment. Theconvection control system further includes a rising edge triggerednegative gauge pressure regulation device comprising pressure controlcircuitry and an associated valve configured to control the first andsecond airflow proportioning devices to open respective airflow paths tothe inner and outer regulated airflow environments. The convectioncontrol system is configured to provide regulated differential pressureforced airflow convection to the inner and outer regulated airflowenvironments with the rising edge triggered negative gauge pressureregulation device, the first and second airflow proportioning devices,and the airflow generation device.

The many embodiments of the present invention described hereincontribute to providing thermal energy transfer (convection) from withinan artificial limb to the ambient atmosphere, which directly reduces theamount of perspiration generated.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an anterior view of the surface area multiplying textile layerwith proximal airflow seal to be attached to a residual limb inaccordance with the present invention.

FIGS. 2A and 2B are an anterior view and a lower cross-sectional view ofthe convection liner to be attached to a residual limb in accordancewith the present invention.

FIG. 3A and FIG. 3B are an anterior view and a cross-sectional view ofthe exterior convection pin adapter, a feature of the convectionartificial limb liner to be attached to a residual limb in accordancewith the present invention.

FIG. 4A and FIG. 4B are a frontal cross-sectional view and a lowercross-sectional view respectively of the airflow artificial limb linerto be attached to a residual limb in accordance with the presentinvention.

FIG. 5A and FIG. 5B are an assembled and partially exploded view of thefour bolt lock housing lamination adapter, a feature of the forceddynamic convection system to be attached to a residual limb inaccordance with the present invention.

FIG. 6A and FIG. 6B are an anterior isometric assembled and partiallyexploded view of the four bolt lock housing lamination adapter andconvection manifold, which are features of the forced dynamic convectionsystem to be attached to a residual limb in accordance with the presentinvention.

FIG. 7A, FIG. 7B, and FIG. 7C are a posterior isometric assembled view,lengthwise cross-section and a partially exploded view of the convectionmanifold, which is a feature of the forced dynamic convection system tobe attached to a residual limb in accordance with the present invention.

FIG. 8 is schematic representation of the convection control system'scircuit board and electromechanical binary airflow proportioningdevices, which are features of the forced dynamic convection system tobe attached to a residual limb in accordance with the present invention.

FIG. 9A, FIG. 9B and FIG. 9C are an assembled, rotated and exploded viewof a mechanical binary airflow proportioning device, which may be afeature of the forced dynamic convection system to be attached to aresidual limb in accordance with the present invention.

FIG. 10 is an anterior view of the exterior liner surface areamultiplying textile layer with proximal airflow seal to be attached to aresidual limb liner in accordance with the present invention.

FIG. 11A and FIG. 11B are an anterior isometric partially assembledview, and a exploded view of the muffler assembly in the convectionmanifold, which is a feature of the forced dynamic convection system tobe attached to a residual limb in accordance with the present invention.

FIG. 12 is an exploded view of the electromechanical binary airflowproportioning housing which is a feature of the forced dynamicconvection system to be attached to a residual limb in accordance withthe present invention.

FIG. 13A and 13B are an anterior view and a cross-sectional view of theexterior convection pin adapter in accordance with another embodimentand a feature of the convection artificial limb liner to be attached toa residual limb in accordance with the present invention.

FIG. 14A and 14B are an isometric assembled and exploded view of aconvection O-ring boss straight barb fitting for tubing, which is afeature of the various components of the dynamic convection system to beattached to a residual limb in accordance with the present invention.

FIG. 15A and 15B are an isometric assembled and exploded view of aconvection O-ring boss rotating barb elbow for tubing, which is afeature of the various components of the dynamic convection system to beattached to a residual limb in accordance with the present invention.

FIG. 16 is an anterior view of the over-molded enclosure for dynamicconvection system components to be to be attached to a residual limb inaccordance with the present invention.

FIG. 17 is an exploded assembly sequence view of the dynamic convectionsystem of a residual limb donning the various components and optionalconfigurations of the system limb in accordance with the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described more fully hereinafter withreference to the accompanying drawings in which preferred embodiments ofthe invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Likenumbers refer to like elements throughout. The dimensions of layers andregions may be exaggerated in the figures for greater clarity.

Referring initially to FIG. 1, the multi-ply surface area multiplyingtextile layer 1 which comprises a five ply distal end knitted layer 4,three ply knitted layer 3 and one ply knitted layer 2, a laminatetransition area 5, a raised annular ring 6, and an airflow seal 7 willnow be described. For example, the five ply layer 4 and the three plylayer 3 are one to two inches long and the one ply layer 2 is typicallysix to fourteen inches long. It is the addition of varying thickness orply of textile material that may constitute an improvement in thisexisting design. The textile layer is continuously cavitated, whichmeans the volume of the textile layer comprises interconnected cavitieswhich are continuous with the exterior of the material, aiding airflow.

As reduced to practice in the Dynamic Air Exchange System, without themulti-ply construction, a textile layer 1, which conforms snugly to theshape of an amputee's stump is laminated with a flexible elastomeric top7 (e.g. silicone), of such a diameter as to conform comfortably andsnugly with the proximal region of an amputee's residuum. The textilelayer 1 is donned directly on the amputee's stump and worn underneaththe system's convection liner (described in FIGS. 2 and 4 below).

The continuously cavitated multi-ply surface area multiplying textilelayer 1 surrounds at least a portion of the residual limb and defines aregulated negative gauge pressure environment between the liner and theresidual limb, which facilitates airflow inside the liner as taught inU.S. Pat. Nos. 8,182,547 and 8,475,537 (to the present inventor), andhereafter will be collectively referenced as the Dynamic Air ExchangeSystem. Negative gauge pressure (vacuum) is commonly expressed in inchesof mercury (″Hg) or millimeters of mercury (mmHg), which is equal totorr. One atmosphere equals 14.7 psia (0 psig), 29.92″ Hg (0″ Hgabsolute), 760 mmHg, 760 torr or 1,013 mbar. The airflow seal 7 of thesurface area multiplying textile layer 1 includes a gently taperedlaminate transition area 5, where the fibers of the textile areadherently intertwined with silicone and terminate at the raised annularring 6. The annular ring 6 and proximal seal area 7 are preferablydevoid of textile fibers, which effectively seals both pressure andairflow. As such the airflow seal 7 is preferably an impervious seal.

An improved feature to this design is the distal multi-ply taperingconstruction as opposed to a single ply monolithic construction. Ply isan industry measure of textile thickness. Sanders J E et al. in the 2012paper titled “Amputee socks: how does sock ply relate to sockthickness?” Prosthet Orthot Int. 2012 Mar; 36(1):77-86, found that oneply averaged 0.7 mm, three ply averaged 1.2 mm and five ply averaged 1.5mm for similar knitted single material textile layers. Ply thickness isan industry convention, rather than a precise measure. Adding a distaltoe constructed of five ply material, followed by a band of three plymaterial transitioning to a single ply material provides an increase inairflow cavities resulting in less air flow resistance inside the linerand thus greater airflow for the system's continuously operating airflowgeneration device of the convection control system. The knittedtransitioning ply layers provide a smooth textile layer without seams ornoticeable ply thickness distortions for user comfort and skin health.

Referring initially to FIG. 2A and the lower cross-sectional viewdepicted in FIG. 2B, the convection liner 8, which has longitudinalscallops 10 on its exterior surface tapering proximally 9, distalexterior airflow channels 11, and configured in this depicted embodimentto have an exterior convection pin adapter 12, with convection holes 13and a hollow convection in 14 will now be described. The convectionliner 8 for artificial limbs includes an elastomeric tubularlimb-conforming flexible liner that has a plurality of longitudinalscallops 10, which taper in width and depth proximally 9 and are influid communication with distal exterior airflow channels 11. FIG. 2Bdepicts a lower cross-sectional view of the convection liner 8, whichillustrates the depth of the concave scallops 10. In the embodimentdepicted in FIG. 2B, the convection liner has a smooth inner surface. Aremovable exterior convection pin adapter 12, ported with airflow holes13 receives a hollow convection pin 14, which attaches to a lockmechanism in the rigid socket frame of an artificial limb and comprisesa distal air outflow port, which is in fluid communication with theconvection manifold assembly of the negative gauge pressure forcedconvection system. The exterior convection pin adapter 12 has aplurality of convection holes 13 in a circular pattern, angled such thatthey feed into a central convection channel, feeding into the hollowconvection pin 14 comprising a distal air outflow port, allowing fluidcommunication with the sealed or unsealed environment between theoutside of the convection liner and the rigid socket frame andultimately, the continuously operating airflow generation device of theconvection control system.

In alternate embodiments, fluid communication with the continuouslyoperating airflow generation device of the convection control system mayexist with the sealed environment between the residuum and the inside ofthe convection liner or the sealed or unsealed environment between therigid socket and the outside of the convection liner or a combination ofboth.

A convection liner without a pin, suspended by atmospheric pressure inthe prosthetic socket, is a potential alternate configuration of thisdesign. The convection liner may be donned over the surface areamultiplying textile layer 1 with airflow seal 7 depicted in FIG. 1 andmay include the inflow and outflow air channels and related ports in theDynamic Air Exchange System. As depicted in FIG. 2A and FIG. 2B, theconvection liner 8 is configured for only airflow over the exterior ofthe liner.

The minimum amount of negative pressure to hold the convection liner onthe residuum as well as to suspend the liner in the artificial limbsocket frame by atmospheric pressure is a function of the weight of theartificial limb divided by the cross-sectional area of the residual limbnear the distal end. A typical transtibial amputee patient may require anegative gauge pressure of 38 mm Hg to securely hold their liner andartificial limb on. It should be noted that 38 mm Hg of negative gaugepressure is achievable with common suction socket designs that date backto the prior art of Dubois Parmelee, Feb. 10, 1863 U.S. Pat. No. 37,637and were subsequently improved with auto expulsion modular valves asreferenced by Charles W. Radcliffe in the 1955 article “FunctionalConsiderations in Fitting the Above Knee Limb.” Art Limbs, Vol. 2, #1p.35-60, which references that 77.6 mm Hg is achievable with autoexpulsion modular valves. Airflow between the liner and the limb andairflow between the exterior of the liner and the artificial limbsocket, created by a continuous negative gauge generation device of theconvection control system requires maintaining the differential pressurelevel of industry standard expulsion valves (in the example above,thirty-eight mmHg) to achieve secure suspension of an artificial limb

The longitudinal scallops 10 and distal exterior airflow channels 11allow efficient thermal energy transfer to occur during forced dynamicconvection and thus act as convection guides. The longitudinal scallops10 also create positive volumetric distortion during stance phase. Theliner expands during weight bearing, effectively increasing the volumeof the socket, due to the expansion provided by the scalloped shape ofthe liner. This has the effect of mitigating residuum shrinkage duringits duration of use. As advances in silicone and textile fabricscontinue, the liner may be constructed from thermally conductivesilicone and the yarns of a potential textile cover (not depicted) maycontain phase change materials, further assisting convection.

Referring to FIG. 3A and the cross-sectional view FIG. 3B, the exteriorconvection pin adapter 12 is depicted, which includes an exteriorthreaded section, 16 and an interior threaded section 18, airflow holes13, wrench flats 15, a central convection channel opening 17 and aninstalled hollow convection pin 14. The exterior airflow convection pinadapter 12 has a plurality of airflow holes 13 in a circular pattern,angled such that they feed into a central convection channel 17,allowing fluid communication with the installed hollow convection pin 14that comprises a distal air outflow port 19, which is in fluidcommunication with the convection manifold (FIGS. 6A and 6B) andultimately the continuously operating airflow generation device. Thehollow convection pin 14 has a broached distal region 20 to receive aninstallation tool. The proximal threaded section 16 of the exteriorconvection pin adapter 12, engages a receiving umbrella within theconvection liner that preferably, does not have a distal air outflowport with occlusion preventing flange installed, (although such aconfiguration is a potential embodiment of this system). Wrench flats 15allow secure installation as well as removal for alternately configuredconvection pin threaded adapters, which change the functionality of thesystem. In the depicted embodiment, this exterior convection pin adapter12 allows forced convection on the outside of the convection liner bythe flow of air over the exterior of the convection liner and itsexterior longitudinal scallops and distal exterior airflow channels,through the convection holes 13, which collect in a central convectionchannel opening 17 and the travels down the distal convection channel 19of the hollow convection pin 14, into a convection manifold andultimately into and expelled from the continuously operating airflowgeneration device of the convection control system. A potentialembodiment of this design would comprise the addition of a convectionliner with a distal air outflow port with occlusion preventing flangeinstalled which would allow simultaneous fluid connection betweenregulated the inner liner environment and the outer liner environment.

Referring to FIG. 4A and FIG. 4B, depicted is the convection liner 8 ina frontal cross-section FIG. 4A and lower cross-section FIG. 4B. In thedepicted embodiment, the convection liner 8, with longitudinal scallops10, has a plurality of internal narrow airflow grooves 22 which begin atthe center level of the at least one proximal air channel inflow portwith occlusion preventing flange 21, of the existing Dynamic AirExchange System, and terminates at the distal air outflow port withocclusion preventing flange 23 also from the Dynamic Air ExchangeSystem. The airflow grooves 22 are situated below the airflow seal andinterface with the multi-ply surface area multiplying textile layer(depicted in FIG. 1), so that airflow is improved with these additionalconvection guides in the convection liner 8 and the sealed negativegauge pressure environment between both the residuum and the convectionliner 8 is maintained. The airflow grooves are of a narrow width, suchthat invagination of the tissue does not occur when wearing themulti-ply surface area multiplying textile layer. Depicted in FIGS. 4Aand 4B are longitudinal grooves, but the airflow grooves may be angled,serpentine, crosshatched, so as to direct negative gauge pressure flowevenly over the surface area of the residuum.

An alternately configured interior convection pin threaded adapter 25threads into a receiving umbrella 24 that is adherently embedded withinthe liner's material construction to create a secure mounting for theconvection pin adapter 25 and convection pin. The interior convectionpin threaded adapter 25 has an axial O-ring gland 27 that seals alongthe face of the mating surfaces of the interior convection pin threadedadapter 25 and receiving umbrella 24. A sealing surface 26 receives anO-ring attached to the convection pin and creates an airtight seal.These sealing designs aim to prevent fluid communication (leaks) betweenthe inside of the liner and the outside of the liner environment.

In this depicted embodiment, this solid interior convection pin threadedadapter 25 allows forced convection on the inside of the convectionliner 8 by the flow of air through the at least one proximal air channelinflow port with occlusion preventing flange 21, over its interiorsurface, which is assisted by the airflow grooves 22 acting asconvection guides and the multi-ply surface area multiplying textilelayer, collecting at the distal air outflow port with occlusionpreventing flange 23 and travels down the distal convection channel ofthe hollow convection pin (not depicted), into a convection manifold andultimately into and expelled from the continuously operating airflowgeneration device of the convection control system. As depicted in FIGS.4A and 4B, the convection liner 8, with the interior convection pinadapter 25 is configured for only airflow over the inside of theconvection liner 8 and the residuum of an amputee.

Referring to FIG. 5A and FIG. 5B, a four bolt lock housing laminationadapter 28 is depicted, which fits a commercially available lockmechanism and plunger (not depicted) providing secure suspension betweenthe liner with convection pin and the rigid socket. The four bolt lockhousing lamination adapter 28 in lamented into the distal end of aprosthetic rigid socket frame comprising, for example, carbon fiber andepoxy. It has the industry standard six millimeter four bolt patternthat modular artificial limb industry components fit. The hollowconvection pin 14, comprising a distal air outflow port, is secured bythis lock mechanism and it passes through the housing to engage anO-ring seal in a convection manifold (depicted in FIGS. 6A and 6B). Amonolithic funnel 29, has a steep angled central conical channel toguide the convection pin 14 into the lock mechanism. A flexible innersocket retaining ring 30 is to be bonded to a flexible inner socketsecured by the rigid socket frame. An O-ring 31 creates an airtight sealbetween the lock mechanism and the flexible inner socket. An O-ring 31resides in a gland 32 in the four bolt lock housing lamination adapter28, and provides a way of securing the flexible liner to the lockmechanism. A flexible inner socket provides patent comfort in anartificial limb as bony prominences can be relieved with socket framefenestrations. A flexible inner socket allows socket fit modifications;for example, pads between the rigid frame and flexible inner socket canadapt the socket to residuum morphological changes over long termperiods of artificial limb use. Creating a flexible inner socket with anairtight seal to the lock mechanism allows airflow from the continuouslyoperating airflow generation device to be directed to the exterior ofthe convection liner, should that embodiment be desired, as well asprovide the opportunity to create a sealed negative gauge pressureenvironment between the exterior of the liner and the socket frame.Should a flexible inner socket not be prescribed for the artificiallimb, a solid spacer can be substituted using O-ring 31 as a method ofsecure attachment.

Referring to FIG. 6A and FIG. 6B, the four bolt lock housing laminationadapter 28 with a monolithic funnel 29 and flexible inner socketretaining ring 30 is shown in a potential anterior assembly relationshipwith the convection manifold housing 33. The convection manifold housing33 can be universally configured in anterior and posterior placement ofports, plugs and fittings on an artificial limb. As depicted in FIG. 6A,the convection manifold housing 33 has an absorbent housing access plug37, which holds an absorbent material to extract moisture from theairflow path, which ultimately passes to the continuously operatingairflow generation device; a pressure signal O-ring boss rotating barbelbow fitting for tubing 36 allows fluid communication to a pressuretransducer; and an optional muffler housing cover plate 34, which issecured by four screws 35. FIG. 6B is a partially exploded view whichdepicts the top surface of the convection manifold housing 33. There arefour load stanchions 38 which bridge between an industry standardpyramid adapter (not depicted) and the four bolt lamination adapter 28,which allows the convection manifold not to bear weight in the systemconstruction. The hollow convection pin 14, which comprises a distal airoutflow port, engages an airtight negative gauge pressure O-ring seal 41housed in an O-ring gland in the convection manifold housing 33, whichallows leak proof fluid communication between the inside of the liner,or outside of the liner or a combination of both and the convectionmanifold housing 33. Should the system embody an optional batteryoperated electric continuously operating airflow generation device, theconvection manifold housing 33 has an exhaust flow annular ring 40 thatmates with an annular ring (not depicted) in the four bolt laminationadapter 28 and is bounded by an inner axial O-ring gland (not depicted)in the four bolt lamination adapter 28, and an outer axial O-ring gland39 in the top surface of the convection manifold housing 33. These twoO-rings (not depicted) create an airtight seal along the mating faces ofthe convection manifold housing 33 and the four bolt lamination adapter28. The exhaust flow annular ring 40 directs exhaust flow to a series ofmuffler baffles (not depicted) on either side of the convectionmanifold, located behind the muffler housing cover plate 34. The mufflerbaffles effectively reduce the noise of a battery operated continuouslyoperating negative gauge pressure pump, should such an optionalembodiment be configured.

Referring to FIG. 7A, FIG. 7B and FIG. 7C, the convection manifoldhousing 33 is shown in a potential assembly of constituent parts in aposterior isometric view, in a lengthwise cross-section and in apartially exploded view respectively. The convection manifold housing 33can be universally configured in anterior and/or posterior placement ofports, plugs and fittings on an artificial limb. In this depiction oneof the potentially two, airflow convection manifold O-ring boss rotatingbarb elbow fitting for flexible tubing 43 directs airflow to thecontinuously operating airflow generation device. A filter housing andspring and poppet leak prevention device threaded plug retainer 44 isaccessible from the posterior of the convection manifold housing 33. Itcreates an airtight seal to the convection manifold housing 33 throughan O-ring 51 retained in an O-ring gland in the filter housing andspring and poppet leak prevention device threaded plug retainer 44,which seals against the sealing area 49 in the convection manifoldhousing 33. Airflow travels down a hollow convection pin which is sealedby an O-ring 41, which is retained in an O-ring gland 45, into amoisture reservoir 46, which is sealed by an O-ring 47 retained in anO-ring gland in the cover plate 48. After depositing moisture dropletsinto the reservoir 46, the airflow travels up around the exposedabsorbent material 56, which is retained by the absorbent housingthreaded access plug 37, which creates an airtight seal to theconvection manifold housing 33 through an O-ring 57 retained in anO-ring gland in the absorbent housing threaded access plug 37, whichseals against the sealing area 50 in the convection manifold housing 33and also provides transducer pressure signal communication through thecenter of the absorbent housing threaded access plug via holes in anannular ring to a pressure signal O-ring boss rotating barb elbowfitting for flexible tubing, exiting the convection manifold housing 33to a transducer on a circuit board. The air then travels to a filtercomplex 55, comprised of two soft O-rings bonded to a stainless steelpleated filter, which fits inside a stainless steel retainer 54, andcreates a direct sealed airflow path to a spring and poppet leakprevention device 52, which is sealed to retainer 54 by O-ring 53. Thespring and poppet leak prevention device 52 has a side sealing O-ring(not depicted) retained in a gland in its housing and fits with anairtight seal inside the filter housing and spring and poppet leakprevention device threaded plug retainer 44. This allows filtered air topass through holes in an annular ring in the filter housing and springand poppet leak prevention device threaded plug retainer, sealed fromenvironmental air by O-ring 51 sealed to the sealing surface 49 of theconvection manifold housing 33 and out one of the threaded exit holes 58to one of the potentially two convection manifold airflow O-ring bossrotating barb elbow fitting for flexible tubing 43.

There are four load stanchions 38, which allow the convection manifoldnot to bear weight. Four high strength forty millimeter long screws inan industry standard M6×1 thread and pitch, pass through thesestanchions and secure an industry standard pyramid adapter (notdepicted) and the four bolt lamination adapter. The exhaust flow pathfrom a potentially battery operated continuously operating airflowgenerating device may require a muffler to address noise issues duringoperation. The exhaust flow is potentially directed through theconvection manifold in an isolated fashion from the airflow generationpathways of the forced dynamic convection system. The exhaust airflowtravels through two separate series of baffles located under the mufflerhousing cover plate 34, which is secured by four screws 35, exhaust flowtravels along matching annular rings in the four bolt lamination adapter(not depicted) and in the convection manifold 40, which is sealed fromenvironmental air to prevent noise by an O-ring in an axial gland 39 andis also bounded by an inner axial O-ring gland in the four boltlamination adapter. Exhaust flow is directed to the two separate seriesof baffles through two downward flow paths 42, which can be arranged invarious configurations in directing the flow of the exhaust relative tothe baffles.

It should be noted that, for convenience, both the absorbent housingthreaded access plug 37 and the filter housing and spring and poppetleak prevention device threaded plug retainer 44 can be removed from theconvection manifold with various coins, e.g. of U.S. currency.

Referring to FIG. 8, depicted is a circuit board constituting theconvection control system 81. It contains circuitry 82 that adjusts theattributes of a continuously operating battery operated airflowgeneration device, as well as a body powered airflow generation device.It also contains circuitry of the rising edge triggered negative gaugepressure regulation device controlling an electromechanical binaryairflow proportioning device 59.

The circuit board 81 plugs into, with surface mount header pins, theelectronic circuits of the Dynamic Air Exchange System. Although itcould be configured as a standalone board, for example, in a potentialconfiguration that solely uses a body powered airflow generation device,as depicted, derives its power from the common battery power source ofthe circuit boards in the Dynamic Air Exchange System and processessignals and modifies the characteristics and behavior of both systemcomponents and electronic designs.

The electronic circuits that comprise the existing Dynamic Air ExchangeSystems can be described as falling edge pressure regulation. A sealedenvironment between the residuum and the liner maintains a static sealednegative gauge pressure. An airflow initiating device is opened by usercommand resulting in lessening of the negative gauge pressure and once aset pressure threshold is crossed by the falling negative gauge pressurelevel, the control circuitry acts to increase the negative gaugepressure by operating an electric airflow generation device in thesealed environment. The present invention controls rising edge negativegauge pressure. A rising negative gauge pressure would be illustrated bythe decreasing absolute pressure of 25.4 mmHg to 152.4 mmHg. A risingedge trigger is a pressure threshold event resulting from risingnegative gauge pressure. For example, upon reaching a set pressurethreshold, a rising edge triggered negative gauge pressure regulationdevice, which may comprise an electromechanical binary airflowproportioning device (solenoid) 59 and associated control circuit 81,will open an electromechanical binary airflow proportioning device,opening an air flow path to the atmosphere. This acts to regulate thepressure in a sealed environment between the limb and liner or the linerand socket or a combination of both. The airflow generation device inthis invention is preferably continuously operating and the negativegauge pressure is regulated by the action of an electromechanical binaryairflow proportioning device 59, or a mechanical spring and poppetmechanism or an one-piece elastomeric valve, relieving the increasingnegative gauge pressure build up. To keep a continuously operatingairflow generation device that is ported to the inside of the liner fromconflicting with the falling edge regulations systems of the existingDynamic Air Exchange System, a non-symmetrical low pass signal filter isactivated during dynamic convection. The filter has a long time constantfor decreasing negative gauge pressure and a fast time constant forincreasing negative gauge pressure, which allows smart filtering of thefalling edge activated, battery operated, pump and associated controlcircuit to function optimally.

The convection control system 81 employs regulated cyclical differentialpressure airflow through continuously operating airflow generationdevice and a rising edge triggered negative gauge pressure regulationdevice. Airflow is directed inside or outside a limb conformableconvection suspension liner, or a combination of both flow paths,through various system architecture configurations, which providesthermal energy transfer from within an artificial limb to the ambientatmosphere. This convection occurs due to temperature difference betweenthe inside of the artificial limb and the ambient atmosphere. The energytransfer of forced dynamic convection mitigates excessive thermalbuildup, which in a linear fashion mitigates the amount of perspirationgenerated.

Efficient energy transfer by forced dynamic convection is achieved byconstant airflow. When a negative gauge pressure pump is employed tomove air by creating a pressure differential and configured to beconstantly operating, it is considered a continuous airflow generationdevice, A continuous airflow generation device comprises either abattery operated design, controlled by unique circuitry 82 to operate ina quiet, energy efficient manner, or a body powered mechanical design,which are specifically configured for artificial limbs and currentlyprovided by various device manufacturers, These mechanical negativegauge pressure pumps are either actuated by body weight or the dynamicsof ambulation.

The electromechanical binary airflow proportioning device 59 is retainedin a receiving block 65, with a cover plate 60 that has occlusionprevention grooves 61 leading into air inlet holes 62 down to a filter(not depicted) which protects the operating mechanism of theelectromechanical binary airflow proportioning device 59. There areeight screws 63, the outermost four retain the assembled housing in therigid socket over-mold, and the innermost four screws retain the coverplate to the receiving block 65, removal of these screws allows accessto the inlet air filter. Depicted are two of at least oneelectromechanical binary airflow proportioning O-ring boss straight barbfittings for tubing 64 could be variously attached to inlet air channeltubing in fluid communication with inlet air channel caps that affix tothe proximal air channel inflow port with occlusion preventing flange(21, FIG. 4B) of the convection liner or to a similar inflow portmounted in the rigid socket frame or the sealed flexible inner socket.The receiving block can be configured up to four electromechanicalbinary airflow proportioning O-ring boss barb fittings for tubing,allowing various system configurations.

The circuit is designed to be potentially configured to control twoelectromechanical binary airflow proportioning devices working in tandemto maintain an adjustable negative gauge pressure in two sealedenvironments, e.g. one dynamically and one statically. The addition ofthe optional airflow path directing electromechanical binary airflowproportioning device 83 allows the negative gauge pressure of thecontinuous airflow generation device to be coupled and decoupled from,for example, the sealed environment between the outside of theconvection liner and the interior of the rigid socket frame or flexibleinner socket. The pressure transducer 75 is in communication with theambient environment as a reference pressure through port 76 and can bedirected to any sealed environment in an artificial limb through port 77to quantize the differential gauge pressure. (Span adjustment 74 allowsfor full scale adjustment of the desired system negative gauge pressurelevel adjustment. Negative gauge pressure sensor zero adjustment 73adjusts for irregularities in the manufacture of the pressure sensor75.) If the transducer were to be ported to a sealed environment on theoutside of the liner and inside the rigid socket, an upper negativegauge pressure threshold adjustment 70 and a lower negative gaugepressure threshold adjustment 69 establishes the operational negativegauge pressure band of this environment's static environment, whilstworking in tandem with the rising edge negative gauge pressureregulating device's electromechanical binary airflow proportioningdevice 59 in the dynamic environment inside of the convection liner.

A circuit operational cycle will now be described; a constantlyoperating body powered pump or battery operated pump generates airflowin a forced convection system configured with the optional secondelectromechanical binary airflow proportioning device 83. The optionalairflow path directing electromechanical binary airflow proportioningdevice 83 acts to control airflow (coupling-decoupling) to either theoutside or inside of the liner. The continuous airflow generation deviceis connected to the common middle port 85, the top port 86 is in fluidcommunication with the sealed environment between the residuum and theliner, and the bottom port 84 is in fluid communication with the sealedor unsealed environment between the outside of the convection liner andthe inside of the rigid socket frame, or flexible inner socket. Theother electromechanical binary airflow proportioning device 59 acts as arising edge triggered negative gauge pressure regulating device, whichallows environmental air into any sealed environment in the artificiallimb, in this example it will be the inside of the convection liner. Thetwo of the at least one electromechanical binary airflow proportioningO-ring boss straight barb fitting for tubing 64 are attached to inletair channel tubing in fluid communication with caps that affix to theproximal air channel inflow port with occlusion preventing flange of theconvection liner. The receiving block 65 can be optionally configuredfor one to four electromechanical binary airflow proportioning deviceO-ring boss straight barb fittings for tubing depending on the systemconfiguration.

Initially, the cycle starts off where the airflow and negative gaugepressure is directed through the common port 85 on through the openbottom port 84 to the sealed environment of outside of the liner and theinside of the rigid socket (or flexible socket), whose upper thresholdof seventy-six mmHg has been adjusted by potentiometer 70 and the lowerthreshold adjusted by potentiometer 69 to a value of thirty-eight mmHg.Once the pressure threshold of seventy-six mmHg has been achieved by theairflow generating device operating in a sealed environment, theoptional air flow path directing electromechanical binary airflowproportioning device 83 decouples the airflow and negative gaugepressure from the inner socket, outside of the liner environment andcouples the continuously operating airflow generation device to theinside of the liner. Inside the sealed inner convection linerenvironment, a rising edge threshold is adjusted by potentiometer 68 toa negative gauge pressure level of eighty-nine mmHg and can be furtherfine-tuned with both a delay in opening adjustment 67 and a delay inclosing adjustment 71, which effectively sets the hysteresis band of thesystem. Once the eighty-nine mmHg threshold is crossed by thecontinuously operating body powered airflow generation device, theelectromechanical binary airflow proportioning device opens and closes,regulating the negative gauge pressure through timed cyclicaldifferential pressure airflow. The pressure transducer 75 is in fluidcommunication with the sealed environment of the outside of theconvection liner and inside the rigid socket through port 77. If thepressure drops below the established lower threshold of thirty-eightmmHg, the airflow path directing optional electromechanical binaryairflow proportioning device 83 decouples the continuously operatingnegative gauge pressure generating device from the inside of the linerand directs it back to the outside of the liner (airflow via bottom port84) until the set upper threshold of seventy-six mmHg is achieved andthen the airflow is coupled back to the inside of the liner (airflow viatop port 86), completing the cycle. It should be noted that a negativegauge pressure level of seventy-six mmHg in the sealed environmentbetween the exterior of the liner and the inside of the socket is anegative gauge pressure level achievable by industry standard autoexpulsion modular valves used in typical suction socket suspensiondesigns.

An over-band safety threshold 72 adjustment is set at the highest levelof negative gauge pressure the residuum can directly tolerate for abrief amount of time. This setting is not intended to be a normaloperational setting of the system; it is a result of some systemcomponent failure. A potential setting might be 203 mmHg. This thresholdwill open the electromechanical binary airflow proportioning device 59,irrespective of the state of the coupling decoupling electromechanicalbinary airflow proportioning device 83, allowing environmental air intosealed environment preventing negative gauge pressure from rising abovethis over-band safety threshold level. There are numerous potentialconfigurations of the convection control system 81. It can be configuredto use only one electromechanical binary airflow proportioning device.The circuit is robust enough to reliably operate multipleelectromechanical binary airflow proportioning devices configured inparallel. Airflow then could be directed to a surge reservoir so thatincreased velocity of forced dynamic convection can be achieved througha configuration those skilled in art will appreciate. The advantage ofdecoupling afforded by the dual binary airflow proportioning devices issafety. If for some reason, the safety threshold, adjusted bypotentiometer 72 is crossed (e.g. a system malfunction), the continuousairflow can be isolated away from the critical environment of theresiduum inside of the liner.

The forced convection circuit board allows the battery operated negativegauge pressure generating device of the existing Dynamic Air ExchangeSystem to be operated as a continuously operating airflow generationdevice. When in forced dynamic convection mode, a unique motor velocityis controlled by potentiometer 78, a unique negative gauge pressurelevel is set by potentiometer 79 and a unique hysteresis band isadjusted by potentiometer 80. These settings are only are active duringforced convection. These adjustable settings are to optimize systemperformance, minimize device noise and conserve battery life.

Referring to FIG. 9A, FIG. 9B and FIG. 9C, illustrated are various viewsof an alternate embodiment of the rising edge triggered negative gaugepressure regulation device. A mechanical binary airflow proportioningdesign 87, which comprises a proximal air channel inflow port withocclusion preventing flange 21 from the existing Dynamic Air ExchangeSystem design, a one-piece elastomeric valve 88, an O-ring 89, retainedin a gland in the detachable cap inlet air channel cap 91 with a filter90. This mechanical binary airflow proportioning design 91 operateswithout the need of a control circuit or battery power. Pressure isregulated by the configuration and action of the one-piece elastomericvalve 88, which is fitted into a recessed crown of the proximal airchannel inflow port with occlusion preventing flange 21. The valve openson increasing negative gauge pressure and closes on decreasing negativegauge pressure. A filter 90 is connected to a detachable inlet airchannel cap 91 which seals with an internal O-ring 88, to create anairtight seal. A mechanical spring and poppet or valve mechanism is analternative potential construction and would act similarly to theone-piece elastomeric valve.

A simplified embodiment of the forced dynamic convection system will nowbe described using a mechanical binary airflow proportioning design. Asocket employing sealed suction suspension is outfitted with a bodypowered airflow generation device connected to the convection manifold(FIGS. 7A-C); a single mechanical binary airflow proportioning device 87is attached to the proximal aspect of a rigid socket. A convection lineroutfitted with a hollow convection pin inserted into an exteriorconvection pin threaded adapter (FIGS. 3A-B) so that airflow is directedto the outside of the liner. With each step, airflow enters the socket,travels along the outside of the convection liner and enters theconvection manifold through the convection pin comprising a distal airoutflow port and out through the body powered negative gauge pressureairflow generation device, achieving thermal transfer with the ambientatmosphere.

An alternate construction would have the mechanical binary airflowproportioning design 87 attached to the convection liner. A body poweredairflow generation device could be connected to the convection manifold(FIGS. 7A-C): a single mechanical binary airflow proportioning device isattached to the proximal aspect of the convection liner which has adistal air outflow port with occlusion preventing flange (FIGS. 4A-B). Amulti-ply surface area multiplying textile layer with airflow sealcovers the residuum and the convection liner has interior convection pinadapter (FIGS. 13A-B), a hollow convection pin, allowing airflow to bedirected only to the inside of the liner. With each step, airflow entersthe sealed environment between the residuum and liner, travels along theinside of the convection liner through the textile layer the liner'sairflow grooves and enters the convection manifold through the hollowconvection pin comprising a distal air outflow port and out through thebody powered negative gauge pressure airflow generation device,achieving thermal transfer with the ambient atmosphere. Experience hasshown that a filter 90 has helped with the reliability of practicalreductions to practice of this embodiment with either an elastomeric onepiece valve 88 or a spring and poppet configuration (not depicted) butan electromechanical binary airflow proportioning configuration with anelectromechanical airflow generating device has proven to be a morereliable fail-safe design.

Referring initially to FIG. 10, an exterior liner surface areamultiplying textile layer with proximal airflow seal 92, which comprisesa monolithic textile layer 93, and optional distal hole 94 for aconvection pin, an impregnated anti-fraying annular region 95, alaminate transition area 5, a raised annular ring 6, and an airflow seal7 will now be described.

The exterior liner surface area multiplying textile layer with proximalairflow seal 92 is intended to be donned over the convection limbconformable liner to improve its airflow capacity and allow an industrystandard sealed suction suspension socket design to be created. A sealedsuction suspension socket might typically have negative gauge pressurelevel of seventy-six mmHg, which is a pressure level that has beenachievable in the artificial limb industry for decades. The exteriorliner surface area multiplying textile layer with proximal airflow seal92 surrounds at least a portion of the exterior surface of theconvection liner and defines a sealed negative gauge pressureenvironment between the exterior liner and the socket, which facilitatesairflow in an industry standard suction suspended socket design. Theairflow seal 7 of the surface area multiplying textile layer 93 includesa gently tapered laminate transition area 5, where the fibers of thetextile are adherently intertwined with silicone and terminate at theraised annular ring 6. The annular ring 6 and proximal seal area 7 aredevoid of textile fibers, which effectively seals both pressure andairflow between the exterior of the convection liner and the interior ofthe artificial limb socket. As such, the airflow seal 7 is preferably animpervious seal. Although monolithic in structure, the exterior textilelayer is also continuously cavitated, which means the volume of thetextile layer comprises interconnected cavities which are continuouswith the exterior of the material, aiding airflow and convection.

The lock housing depicted in FIG. 5A and FIG. 5B and the convectionmanifold depicted in FIG. 7A-C allows a hollow convection pin to beused, while maintaining an airtight seal in the socket. The proximalseal area 7 of the exterior liner surface area multiplying textile layer92 creates an airtight seal between the exterior liner and theprosthetic socket. A rising edge binary airflow proportioning device(FIG. 8 and FIG. 9A-C) would be attached to the socket (or flexibleinner socket) aligned with the level of the textile layer 93 on theexterior liner, so that a cyclical differential pressure airflow intothe sealed environment between the exterior liner and the socket willachieve forced dynamic airflow convection while maintaining the sealnecessary for a suction suspension socket. Regarding the hollowconvection pin, it is a redundant suspension mechanism as well as adistal convection channel. The distal hole 94 in the textile layer 93 isreinforced with a flat elastomeric impregnated annular region 95 toprevent fraying of the knitted yarns of the textile layer 93.

Referring to FIG. 11A and 11B, depicted is an potential anteriorisometric and exploded view of the convection manifold housing 33, withthe muffler housing cover plate 34 and screws 35 removed to reveal thelocation and order of the exhaust air baffles 97, 99, spacers 96, 98 andtransition plates 100. The convection manifold housing 33 and mufflerflow paths can be universally configured in anterior and/or posteriorplacement of ports, plugs and fittings on an artificial limb. Theexhaust air baffles are configured with either four flow holes 97 orfive flow holes that are countersunk to reduce airflow resistance andare of a sufficient sized diameter to minimize backflow pressure to apotentially configured battery operated negative gauge pressure airflowgenerating device. Forced dynamic convection employs regulated cyclicaldifferential pressure airflow, which necessitates a continuouslyoperating airflow generation device (and a rising edge triggerednegative gauge pressure regulation device). A continuously operatingbattery powered negative gauge airflow generation device necessitates amuffler on its exhaust side to minimize its operational noise,

Depicted for reference, a pressure signal O-ring boss rotating barbelbow fitting for tubing 36 allows fluid communication to a controlcircuit pressure transducer. The absorbent housing accesses plug 37,which holds an absorbent material to extract moisture from the airflowpath is also depicted. It should be noted that the airflow and exhaustflow paths in the convection manifold design are isolated from eachother.

There are two rows of ten baffles on either side of the convectionmanifold. Exhaust air from the negative gauge airflow generating deviceenters from a face sealing elbow barb 101 on the anterior aspect of theconvection manifold, goes through various spacers and baffles until itreaches a transition plate 100 which directs the exhaust flow upward tothe top of the convection manifold, via one of the two connecting holes42 and around through an annular ring 40, and back down into theopposite side of baffles through an identical transition plate 100,which directs the exhaust flow to the baffles and spaces on the otherside of the convection manifold, making a “Z” flow path. A “U” flow pathis an optional configuration. Airflow exits out through the posterior ofthe convection manifold and sound waves can be further attenuated with abreather fitting, additional tubing or holes through the muffler coverplate 34.

Referring to FIG. 12, an exploded view of the electromechanical binaryairflow proportioning housing is depicted. The electromechanical binaryairflow proportioning device 59 is to be mounted in a receiving block65, with a cover plate 60 that has occlusion prevention grooves 61leading into air inlet holes 62. A filter 102 protects the operatingmechanism of the electromechanical binary airflow proportioning device59 from debris. There are eight screws 63, the outermost four retain theelectromechanical binary airflow proportioning device's housing in therigid socket over-mold, and the innermost four screws retain the coverplate to the receiving block 65, removal of these screws allows accessto the inlet air filter. Two of at least one electromechanical binaryairflow proportioning O-ring boss straight barb fitting for tubing 64could be variously attached to inlet air channel tubing in fluidcommunication with inlet air channel caps that affix to the proximal airchannel inflow port with occlusion preventing flange (21, FIG. 4B) ofthe convection liner or to a similar inflow port mounted in the rigidsocket frame or the sealed flexible inner socket. A block O-ring bossplug 103 seals an optional flow path, forward of the operating mechanismof the electromechanical binary airflow proportioning device 59, toallow multiple solenoids to be in fluid communication with each other.The receiving block can be ultimately configured for fourelectromechanical binary airflow proportioning O-ring boss straight barbfitting for tubing 64 depending on the system configuration.

Referring to FIG. 13A and 13B, a removable interior convection pinadapter 25 is depicted with an interfacing hollow convection pin 14,which comprises a central convection channel 105, O-ring axial seal 27and O-ring sealing gland surface 26 to the convection pin 14, threads106 to receive an interfacing convection pin 14 and threads 104 forinstallation into an umbrella allowing attachment to the convectionliner. Wrench flats 103 allow secure installation as well as removal foralternately configured convection pin threaded adapters, which canchange the functionality of the system. The hollow convection pin 14 hasa broached distal region 20 to receive an installation tool forinterfacing with the interior convection pin adapter 25 as well asprovide an airtight thread seal with an O-ring 107. In the depictedembodiment, this interior convection pin adapter 25 allows forcedconvection on the inside of the convection liner by the flow of air overthe interior of the convection liner and its interior convectionchannels as well as through the residuum donned tapering textile layerwith proximal airflow seal, through a central convection channel 105 andthen travels down the distal convection channel 19 of the hollowconvection pin 14, into a convection manifold and ultimately into andexpelled from the continuously operating airflow generation device ofthe convection control system.

Depicted in FIG. 14A and FIG. 14B is a convection O-ring boss straightbarb fitting for tubing 108, which comprises a tubular post and barb tosecure tubing 113, a hexagonal section 112 to receive an installationtool, an O-ring sealing gland surface gland 114, and O-ring 110,mounting threads 109 for various interfacing installations and a centralair passageway 111. In some configurations air flows through a centralair passageway configured through its axial center 111 similar toindustry standard barb fitting designs for flexible tubing and in someembodiments, internal geometry is removed so that it functions as asolid plug. Flexible tubing is inserted over the projecting tubular postand barb 113 and securely retained and sealed by its designconfiguration. Most barb fittings for tubing employ an axial sealingO-ring to seal along the mating surfaces of the barb and theinstallation. The problem with such a seal, commonly referred to as aface seal, is that slight over torqueing of a standard barb fitting intosoft materials, for example plastic, can easily deform the sealing faceresulting in negative gauge pressure leaks. This depicted configurationsolves the problem by providing a design where the O-ring 110 seals to asealing surface provided below the surface of the face of theinstallation, which is recessed and protected from damage, resulting ina leak tight connection. Boss is a descriptive term employed for thisdesign; the threaded area 109 plus the O-ring sealing gland surface 114is longer than a typical barb fitting and in certain reductions topractice a boss, or a projection above the surface of the installationis thusly required. In this dynamic convection system specification,barb fittings for tubing are numbered uniquely to aid in the descriptionof their respective airflow direction, function and or ports.

Referring to FIG. 15A and FIG. 15B, depicted is a convection O-ring bossrotating barb elbow for tubing 115, which comprises a hexagonal rotatinghousing with tubular post and barb 120 to receive and secure tubing, anO-ring sealing gland surface gland 118, and O-ring 117, mounting threads116 for various interfacing installations and an air passageway 124,which is in fluid communication with the hexagonal rotating housing withtubular post and barb 120, a retaining nut 121, a hexagonal region 119to receive an installation tool, two O-rings 122, retained in glands 123to seal the hexagonal rotating housing with tubular post and barb 120and the airflow transition holes 124A. In a dynamic convection system,continual mass airflow may be preferred, this design is optimized tominimize airflow resistance via a plurality of airflow transition holes124A, which directs airflow in the O-ring 122 sealed internal chamber ofthe rotating barb housing, transitioning the flow of air ninety degrees.An O-ring 117 seals to a sealing surface below the surface of the faceof the installation, which is recessed and protected from damage,resulting in a leak tight connection. Boss is a descriptive termemployed for this design; the threaded area 116 plus the O-ring sealinggland surface 118 is longer than a typical barb fitting and in certainreductions to practice a boss, or a projection above the surface of theinstallation is thusly required. In this dynamic convection systemspecification, O-ring boss rotating barb elbows for tubing are numbereduniquely to aid in the description of their respective airflowdirection, function and or ports.

Referring to FIG. 16, depicted is an assembled potential embodiment ofthe dynamic convection system for artificial limb. An over-molded socketsystem 125, which comprises an exterior composite or thermoplastic shell126, which conforms and attaches to a rigid artificial limb socket 127,and provides an enclosure area 128 for the potential battery operatedairflow generation device, system control buttons 129, a batteryretaining housing with electrical connections 130 and battery 131, anarea for mounting the electromechanical rising edge negative gaugebinary airflow proportioning device, whose cover 60, is mounted on topof the composite or thermoplastic shell 126 and a place to retain thesystem circuit boards 132. For visual reference, a lock release plunger135 is also depicted. Air into the sealed regulated environment betweenthe residuum and the inner liner, as configured in this depiction,passes through the cove 60 and filter of the opened electromechanicalbinary airflow proportioning device, through one of the potentialmultiple electromechanical binary airflow proportioning O-ring bossstraight barb fittings for tubing 64 attached to inlet air channeltubing 136, connected by the channel cap O-ring boss straight barbfittings for tubing 137 allowing fluid communication with inlet airchannel cap 91 that is interfaced with the proximal air channel inflowport with occlusion preventing flange attached to the convection liner8. The inflow air tubing 133 of the battery operated continuous airflowgenerating device is in fluid communication with the convection manifoldhousing 33 via the convection manifold O-ring boss rotating barb elbowfitting for flexible tubing 43. The convection manifold housing 33 canbe universally configured in anterior and posterior placement of ports,plugs and fittings on an artificial limb. In this depiction the filterhousing and spring and poppet leak prevention device threaded plugretainer 44 is assembled in an anterior placement. The battery operatedcontinuous airflow generation device exhaust is connected via exhausttubing 134 to an anteriorly placed industry standard face sealing elbowbarb 101, which directs the exhaust flow to a series of baffles oneither side of the convection manifold to minimize operational noise.The main advantage of an over-molded socket system is the advantageousweight distribution of the dynamic air exchange system. Weight placedcloser to the axis of rotation has less of a pendulum effect and isbetter tolerated by the system user. When compared to other enclosureapproaches, for example a box mounted on a pylon of the artificial limb,balance and proprioception are least disrupted by having the systemcomponent weight carried in the over-molded artificial limb socketsystem.

Referring to FIG. 17, the dynamic convection system includes severalunique device designs that may be appreciated alone or in systemcombination. Specifically depicted, an amputee's residual limb 138 willhave a multi-ply textile layer with airflow seal 1, donned on it, uponwhich a limb conformable convection liner 8 with longitudinallyscalloped convection grooves and at least one inflow and outflow airchannel is further donned over the residuum 138 and multi-ply textilelayer with airflow seal 1 to define an interior regulated convectionenvironment. Optional system configurations are available to the uservia different convection pin threaded adapters 12 and 25 interfacingwith the convection liner and a hollow convection pin 14. A potentialexterior liner textile layer with airflow seal 92, which defines aregulated negative gauge pressure environment between the outside of theconvection liner 8 and the rigid socket with an over-molded socketsystem 125 may also be provided. The over-molded socket system housessystem components, including circuit boards, battery, electromechanicalairflow proportioning device in fluid communication with the at leastone air inflow channel of the convection liner 8. The system user canemploy a dynamic convection system configuration that uses a batterypowered continuously operating airflow generation device 139 or a bodypowered continuously operating airflow generation device 140 or acombination of both. The body powered continuously operating airflowgeneration device 140 is an air cylinder configured to generatedifferential pressure airflow with each step of an artificial limb. Itis intended to represent industry available continuously operating,while ambulating, body powered negative gauge pressure airflowgenerating devices.

The details and specifications of the multi-ply textile layer 1 can befound in the description of FIG. 1. The details and configuration of theconvection liner 8 can be found in the description of FIG. 2A-2B, andFIG. 4A-4B. The system options offered by the convection pin threadedadapter 12 can be found in the description of FIG. 3A-3B. Likewise, thesystem options for the convection pin threaded adapter 25 can be foundin the description of FIG. 13A-B. The details and configuration of theexterior textile layer with airflow seal 92 can be found in thedescription of FIG. 10. The control circuit of the electromechanicalairflow proportioning device located in the over-molded socket system125 is discussed in detail in the description of FIG. 8 and FIG. 12.Fluid connections from the electromechanical airflow proportioningdevice are made by convection O-ring boss straight barb fitting fortubing as depicted in FIG. 14A and FIG. 14B. An optional mechanicalairflow proportioning device, which would be attached to either theconvection liner 8, or the rigid socket, to which the over-molded system125 attaches is discussed in the description of FIG. 9. The four boltconnection plate of the rigid socket, which the over-molded socketsystem is attached, is presented in the discussion of FIGS. 5A-5B. Theconvection manifolds attachment and fluid communication with the fourbolt connector plate is covered in the description of FIG. 6A-6B. Theconvection manifold, which is also in fluid communication with thecircuit board and the potentially configured battery poweredcontinuously operating airflow generation device with both itscontinuous inflow airflow and exhaust outflow, housed in the over-moldedsocket system is explored in FIGS. 7A-C, and FIG. 11A-B. Fluidconnections to the manifold are made by convection O-ring boss rotatingbarb elbow for tubing as depicted in FIG. 15A and FIG. 15B. Theover-molded socket system is depicted in FIG. 16 of this specification.

This artificial limb design can be configured to be used on above knee,below knee and upper extremity amputees, as would be appreciated bythose skilled in the art. Many modifications and other embodiments ofthe invention will come to the mind of one skilled in the art having thebenefit of the teachings presented in the foregoing descriptions and theassociated drawings. Therefore, it is to be understood that theinvention is not to be limited to the specific embodiments disclosed,and that modifications and embodiments are intended to be includedwithin the scope of the appended claims.

That which is claimed is:
 1. A forced convention system configured to beattached to a residual limb of an amputee, the system comprising: aconformable convection liner configured to be donned over the residuallimb and define an inner regulated airflow environment between the linerand the residual limb; a limb socket configured to receive the residuallimb and donned liner, and define an outer regulated airflow environmentbetween the socket and the liner; an airflow generation device coupledto the inner airflow regulated environment and the outer regulatedairflow environment and configured to generate airflow within the innerregulated airflow environment and the outer regulated airflowenvironment; a convection control system including convection controlcircuitry configured to adjust the airflow generation device andconfigured to dynamically control airflow within the inner regulatedairflow environment and the outer regulated airflow environment tomaintain negative gauge pressure therein and transfer thermal energytherein to an external atmosphere; and a first airflow proportioningdevice coupled to the inner regulated airflow environment, and a secondairflow proportioning device coupled to the outer regulated airflowenvironment; wherein the convection control system further includes arising edge triggered negative gauge pressure regulation devicecomprising pressure control circuitry and an associated valve configuredto control the first and second airflow proportioning devices to openrespective airflow paths to the inner and outer regulated airflowenvironments; and wherein the convection control system is configured toprovide regulated differential pressure forced airflow convection to theinner and outer regulated airflow environments with the rising edgetriggered negative gauge pressure regulation device, the first andsecond airflow proportioning devices, and the airflow generation device.2. The forced convection system according to claim 1, wherein the linerincludes inflow air channels and at least one outflow air channel influid communication with the inner regulated airflow environment; andwherein the airflow generation device is coupled to the inner airflowregulated environment via the inflow air channels and/or the outflow airchannel.
 3. The forced convection system according to claim 1, whereinthe airflow generation device comprises a battery operated airflowgeneration device or a body powered airflow generation device.
 4. Theforced convection system according to claim 1, further comprising atextile layer, including a proximal seal, configured to surround atleast a portion of the residual limb and, with the liner, define theinner regulated airflow environment between the liner and the residuallimb.
 5. The forced convection system according to claim 4, wherein thetextile layer has a thickness that tapers from a distal end to aproximal end thereof.
 6. The forced convection system according to claim1, further comprising a plurality of airflow convection guides on theexterior surface of the liner and comprising longitudinal scallopedchannels in fluid communication with respective distal airflow channels.7. The forced convection system according to claim 6, wherein thelongitudinal scalloped channels are configured to provide positivevolumetric distortion within the socket during a stance phase of theamputee.
 8. The forced convection system according to claim 1, whereinthe liner further includes a convection pin adapter at a distal endthereof and including a central convection channel configured to providefluid communication between the inner regulated airflow environment andthe airflow generation device, and a plurality of adapter convectionholes configured to provide fluid communication between the outerairflow regulated environment and the central convection channel.
 9. Theforced convection system according to claim 8, wherein the liner furtherincludes internal airflow convection guides on an interior surfacethereof and in fluid communication with the central convection channelof the convection pin adapter at the distal end of the liner.
 10. Theforced convection system according to claim 8, further comprising ahollow convection pin interfaced with the convection pin adapter andincluding a distal outlet port in fluid communication with the centralconvection channel of the adapter.
 11. The forced convection systemaccording to claim 10, further comprising a convection manifoldconfigured to interface with the hollow convection pin and including aremovable absorber configured to extract moisture from airflow in anairflow path to the airflow generation device.
 12. The forced convectionsystem according to claim 10, wherein the convection manifold includes amuffler configured to reduce noise in the airflow path.
 13. The forcedconvection system according to claim 1, wherein each of the first andsecond airflow proportioning devices comprises an electromechanicalbinary airflow proportioning device.
 14. The forced convection systemaccording to claim 1, wherein each of the first and second airflowproportioning devices comprises a mechanical binary airflowproportioning device.
 15. A method of forced convection to a residuallimb of an amputee with an attached artificial limb, the methodcomprising: providing a conformable convection liner to be donned overthe residual limb and defining an inner regulated airflow environmentbetween the liner and the residual limb; receiving the residual limb anddonned liner in a limb socket, and defining an outer regulated airflowenvironment between the socket and the liner; coupling airflowgeneration device to the inner regulated airflow environment and theouter regulated airflow environment and configured to generate airflowwithin the inner regulated airflow environment and the outer regulatedairflow environment; and providing a convection control system includingconvection control circuitry configured to adjust the airflow generationdevice to dynamically control airflow within the inner regulated airflowenvironment and the outer regulated airflow environment to maintainnegative gauge pressure therein and transfer thermal energy therein toan external atmosphere; and coupling a first airflow proportioningdevice to the inner regulated airflow environment, and a second airflowproportioning device to the outer regulated airflow environment; whereinthe convection control system further includes a rising edge triggerednegative gauge pressure regulation device comprising pressure controlcircuitry and an associated valve configured to control the first andsecond airflow proportioning devices to open respective airflow paths tothe inner and outer regulated airflow environments; wherein theconvection control system is configured to provide regulateddifferential pressure forced airflow convection to the inner and outerregulated airflow environments with the rising edge triggered negativegauge pressure regulation device, the first and second airflowproportioning devices, and the airflow generation device.
 16. The methodaccording to claim 15, wherein the liner includes inflow air channelsand at least one outflow air channel in fluid communication with theinner regulated airflow environment; and wherein the airflow generationdevice is coupled to the inner regulated airflow environment via theinflow air channels and/or the outflow air channel.
 17. The methodaccording to claim 15, wherein the airflow generation device comprises abattery operated airflow generation device or a body powered airflowgeneration device.
 18. The method according to claim 15, furthercomprising installing a textile layer, including a proximal seal, tosurround at least a portion of the residual limb and, with the liner,define the inner regulated airflow environment between the liner and theresidual limb.
 19. The method according to claim 15, wherein each of thefirst and second airflow proportioning devices comprises anelectromechanical binary airflow proportioning device.
 20. The methodaccording to claim 15, wherein each of the first and second airflowproportioning devices comprises a mechanical binary airflowproportioning device.